#!/usr/bin/env python3
"""Build the dashboard image through Portainer, then trigger GitOps redeploy."""
from __future__ import annotations

import io
import json
import os
import tarfile
import urllib.error
import urllib.request
from pathlib import Path

PORTAINER_URL = os.environ["PORTAINER_URL"].rstrip("/")
PORTAINER_KEY = os.environ["PORTAINER_API_KEY"]
ENDPOINT_ID = 17
STACK_NAME = "arena-dashboard"
IMAGE = "arena-dashboard:latest"
ROOT = Path(__file__).resolve().parents[2]


def request(path: str, *, method: str = "GET", data: bytes | None = None,
            content_type: str | None = None, timeout: int = 60):
    headers = {"X-API-Key": PORTAINER_KEY}
    if content_type:
        headers["Content-Type"] = content_type
    req = urllib.request.Request(
        f"{PORTAINER_URL}/api{path}", data=data, headers=headers, method=method
    )
    try:
        with urllib.request.urlopen(req, timeout=timeout) as response:
            body = response.read()
            return response.status, body
    except urllib.error.HTTPError as exc:
        detail = exc.read().decode("utf-8", "replace")
        raise RuntimeError(f"Portainer HTTP {exc.code}: {detail}") from exc


def build_context() -> bytes:
    buf = io.BytesIO()
    with tarfile.open(fileobj=buf, mode="w") as archive:
        for path in ROOT.rglob("*"):
            if not path.is_file() or ".git" in path.parts:
                continue
            archive.add(path, arcname=path.relative_to(ROOT).as_posix())
    return buf.getvalue()


def build_image() -> None:
    _, raw = request(
        f"/endpoints/{ENDPOINT_ID}/docker/build?t={IMAGE}&dockerfile=Dockerfile&rm=true",
        method="POST",
        data=build_context(),
        content_type="application/x-tar",
        timeout=600,
    )
    errors = []
    for line in raw.decode("utf-8", "replace").splitlines():
        try:
            event = json.loads(line)
        except json.JSONDecodeError:
            continue
        if event.get("error"):
            errors.append(event["error"])
        if event.get("stream"):
            print(event["stream"], end="")
    if errors:
        raise RuntimeError("image build failed: " + "; ".join(errors))


def redeploy_stack() -> None:
    _, raw = request("/stacks")
    stacks = json.loads(raw)
    stack = next(
        (item for item in stacks
         if item.get("Name") == STACK_NAME and item.get("EndpointId") == ENDPOINT_ID),
        None,
    )
    if stack is None:
        raise RuntimeError(f"Portainer stack {STACK_NAME!r} was not found")

    # GitOps polling sees the pushed commit. ForceUpdate also makes later polls
    # recreate the service from the local image built by this workflow.
    payload = {
        "RepositoryReferenceName": "refs/heads/main",
        "RepositoryAuthentication": False,
        "TLSSkipVerify": False,
        "Env": stack.get("Env") or [],
        "AutoUpdate": {
            "Interval": "5m",
            "Webhook": "",
            "ForceUpdate": True,
            "ForcePullImage": False,
        },
    }
    request(
        f"/stacks/{stack['Id']}/git?endpointId={ENDPOINT_ID}",
        method="POST",
        data=json.dumps(payload).encode(),
        content_type="application/json",
        timeout=300,
    )
    print(f"Redeploy requested for stack {stack['Id']}")


if __name__ == "__main__":
    build_image()
    redeploy_stack()